'Metamaterials' Control Sound Waves
Duke University-developed “metamaterials” are structures that can control all sorts of energy waves, with applications ranging from invisibility cloaks to wireless communications. Steve Cummer, professor of electrical and computer engineering, explains how he is using metamaterials to manipulate sound waves. The bright plastic structures his team makes with 3D printing can be arranged in various configurations to obtain different results. The interiors of the plastic blocks contain shapes that force sound waves to take paths of varying lengths. His team's work could allow for more energy-efficient ultrasound imaging devices.